The present invention relates to a washing machine for washing and rinsing by agitating blades which rotate at low speed, and dewatering by high speed rotation of a dewatering tank.
Conventionally, a washing machine was composed as shown in FIG. 31 and FIG. 32. Its constitution is described below.
As shown in FIG. 31, in an outer casing 1, an outer tank 3 is supported by a suspension 2, and a dewatering tank 4 serving also as a washing tank (hereinafter called dewatering tank 4) is provided in the outer tank 3. The dewatering tank 4 is opened at the top, so that the laundry can be loaded from the top. Agitating blades 5 are provided in the bottom, and multiple holes are opened in the side wall.
The dewatering tank 4 is fixed on a dewatering shaft 7 supported by a bearing 6 provided in the bottom of the outer tank 3. The agitating blades 5 are fixed on a washing shaft 9 supported by a bearing 8 inside of the dewatering shaft 7. This washing shaft 9 is connected to a reduction mechanism 10, and a pulley 12 is fitted to a washing side input shaft 11. In the mounting part of the pulley 12 of the washing side input shaft 11, four sides are cut off, and the mounting hole of the pulley 12 has a fitting shape, and the torque of the pulley 12 is transmitted. The pulley 12 is connected to a drive motor 14 through a belt 13. The washing side input shaft 11 has a clutch mechanism 15 for transmitting the rotation of the drive motor 14 by changing over to the washing shaft 9 or dewatering shaft 7.
The clutch mechanism 15 comprises, as shown in FIG. 32, a clutch input boss 15d having a hole in a shape to be fitted into the cut portion of the four sides provided in the washing side input shaft 11, a clutch spring 15b, a control pawl 15e formed by bending the end of the clutch spring 15b, a release sleeve 15c having a notch for fitting the control pawl 15e formed by bending the end of the clutch spring 15b, clutch drive means 15a to be engaged with a stopper 15f of the release sleeve 15c, and a clutch output boss 15g of the dewatering shaft 7 on which the clutch spring 15b is wound.
In this constitution, in the washing and rinsing stroke, when the clutch drive means 15a of the clutch mechanism 15 is engaged with the stopper 15f of the release sleeve 15c, and the control pawl 15e formed by bending the end of the clutch spring 15b is fixed, the clutch spring 15b cannot be wound around the clutch input boss 15d, and if the clutch input boss 15d rotates, rotation cannot be transmitted to the clutch output boss 15g of the dewatering shaft 7. Rotation of the drive motor 14 is transmitted only to the agitating blades 5 through the washing shaft 9, and mechanical force is given to the laundry. Thus, washing and rising of the laundry contained in the dewatering tank 4 are progressed.
In the dewatering stroke, when the clutch drive means 15a of the clutch mechanism 15 is disengaged from the stopper 15f of the release sleeve 15c, and the control pawl 15e formed by bending the end of the clutch spring 15b is set free, the clutch spring 15b is wound around the clutch input boss 15d. Accordingly, when the clutch input boss 15d rotates, rotation is transmitted to the clutch output boss 15g of the dewatering shaft 7. Rotation of the drive motor 14 is transmitted only to the dewatering tank 4 through the dewatering shaft 7, and the entire dewatering tank 4 is put into rotation. As the dewatering tank 4 rotates, the water in the laundry after washing and rinsing is wrung out by centrifugal force into the outer tank 3 through multiple holes opened in the side wall of the dewatering tank 4. Thus, the laundry is dewatered automatically.
In such conventional washing machine, the drive motor 14 is transmitting power to the reduction mechanism 10 through the belt 13. Accordingly, if one attempts to apply a larger mechanical force to the laundry in order to increase the washing capacity or to enhance the cleaning power, transmission torque is defined by the upper limit by belt slip, belt elongation, belt breakage, or tension changes of the belt 13 due to time-course changes, and transmission torque corresponding to large capacity cannot be obtained.
Moreover, since heavy objects, that is, the drive motor 14 and the reduction mechanism 10, are disposed side by side beneath the outer tank 3, the position of the center of gravity of the dewatering tank 4 and outer tank 3 suspended in the outer casing 1 is deviated from the center of rotation (dewatering shaft 7) of the dewatering tank 4. Therefore, in dewatering rotation of the dewatering tank 4, the balance is likely to be broken, and vibration due to rotation becomes larger.
To solve such problems, a washing machine constituted as shown in FIG. 33 has been proposed.
As shown in FIG. 33, an outer tank 16 is suspended by a plurality of suspensions 18 in an outer casing 17, and inside of the outer tank 16. Moreover, there is a dewatering tank 20 serving also as washing tank (hereinafter called dewatering tank 20) which is fixed to the upper end side of a dewatering shaft 19 and is rotated by the dewatering shaft 19. At the side of the dewatering tank 20, a plurality of water passing holes 21 are formed, and a liquid balancer 22 is disposed at the upper opening, so that the laundry may be loaded through the upper opening.
A bearing 21 supports the dewatering shaft 19, and is provided in the bottom of the outer tank 16. A washing shaft 24 is disposed inside of the hollow dewatering shaft 19, and is disposed to be coaxial with the dewatering shaft 19. At the upper end of the washing shaft 24, agitating blades 25 are provided rotatably in the inner bottom of the dewatering tank 20, and a rotor 27 of a drive motor 26 is connected to the lower end. The drive motor 26 comprises the rotor 27 and a stator 28 disposed oppositely to a magnet provided on the outer circumference of this rotor 27, and the rotor 27 is rotated by the rotary magnetic field of the stator 28. Between the lower end of the dewatering shaft 19 and the rotor 27, a clutch mechanism 30 is provided through a coupling 29, and by changing over the clutch mechanism 30, rotation of the rotor 27 is transmitted or not transmitted to the dewatering shaft 19.
In this constitution, in the washing and rinsing stroke, the clutch mechanism 30 is changed over, and the dewatering shaft 19 and rotor 27 are cut off. Therefore, the rotation of the rotor 27 of the drive motor 26 is transmitted only to the agitating blades 25 through the washing shaft 24, and a mechanical force is given to the laundry. Thus, washing and rinsing of the laundry contained in the dewatering tank 20 are progressed.
In the dewatering stroke, the water in the dewatering tank 20 is discharged, the clutch mechanism 30 is changed over, and the dewatering shaft 19 and rotor 27 are coupled, thereby rotating the washing shaft 24, dewatering shaft 19 and dewatering tank 20 coupled to the rotor 27 of the drive motor 26. As the dewatering tank 20 rotates, the water in the laundry after washing and rinsing is wrung out into the water tank 16 from multiple water passing holes 21 provided in the side of the dewatering tank 20 by centrifugal force. Thus, the laundry is dewatered.
In the washing machine of such constitution, however, in order to effectively suppress any imbalance in the dewatering stroke, the center of rotation of the dewatering shaft 19 and the washing shaft 24 were disposed coaxially with the rotary shaft of the drive motor 26 by using a coupling 30. The position of center of gravity of the dewatering tank 20 and outer tank 16 was also matched nearly with the position of center of gravity of the drive motor 26. It therefore required alignment of the coupling 30, the assembling performance was poor, and the washing machine was higher by the portion of the height of the coupling 30, which added to the cost.
The invention is to solve the problems of the prior arts, and it is an object thereof to present a washing machine capable of increasing the rotating torque of the agitating blades without increasing the torque of the drive motor, and capable of coping with an increase of the washing capacity, while avoiding an increase in the size of the drive motor, by suppressing eccentricity to the washing side input shaft if the laundry collides against the agitating glades.
In the invention, to achieve the above objects, a washing shaft for rotating the agitating blades disposed in a dewatering tank is disposed coaxially on a hollow dewatering shaft for rotating the dewatering tank, the washing shaft is connected to the output side of a reduction mechanism, a washing side input shaft is connected to the input side of the reduction mechanism to rotate the washing shaft by decelerating the rotation of the drive motor, and a rotor of the drive motor is coupled to the lower part of the washing side input shaft. In this constitution, therefore, since the agitating blades are rotated by reducing the rotating speed of the drive motor by the reduction mechanism, the rotating torque of the agitating blades can be increased without increasing the torque of the drive motor. If the laundry collides against the agitating blades, the eccentricity of the washing shaft is absorbed by the reduction mechanism, and eccentricity of the reduction mechanism to the washing side input shaft can be suppressed. In addition, the eccentricity of the rotor coupled to this input shaft is suppressed, the gap between the rotor and stator is decreased, a size increase of the drive motor is avoided, and a washing machine capable of coping with an increase of washing capacity is presented. Moreover, since the rotor is coupled directly to the washing side input shaft, the bearing of the washing side input shaft can be used commonly without particularly installing a bearing for the drive motor.
Preferably, the reduction mechanism and drive motor are disposed coaxially, and the clutch mechanism for transmitting or not transmitting the rotation of the drive motor to the dewatering shaft is composed of a torque transmitting unit for transmitting rotation of the drive motor to the dewatering shaft and a drive unit for contacting with or departing from the torque transmitting unit. In this embodiment, part of the torque transmitting unit is formed in the rotor of the drive motor. Therefore, the position of the center of gravity the of dewatering tank and the outer tank and the center of rotation of the dewatering tank can be matched, generation of imbalance in dewatering can be suppressed, and the belt is not necessary so therefore problems caused by the belt are eliminated. Moreover, since part of the torque transmitting unit of the clutch mechanism is formed in the rotor of the drive motor, the number of parts is decreased and the assembling performance is enhanced, the clutch mechanism is reduced in thickness and size. Therefore, an increase of capacity in the lower part of the main body of the washing machine can be suppressed.
More preferably, the drive motor is composed of a rotor, a stator, and a stator housing, and the stator housing is held in the case incorporating the dewatering shaft. In this constitution, the assembling performance is enhanced by eliminating matching of axial centers of the drive motor, dewatering shaft and washing shaft, or by a gap adjustment of the rotor and stator. Moreover, the gap between the rotor and stator is reduced, and an increase in the size of the drive motor is avoided. Hence, it is possible to cope with an increase of washing capacity without adding to the cost.
Further preferably, in the constitution in which the reduction mechanism and drive motor are disposed coaxially, the clutch mechanism is disposed inside of the stator housing for composing the drive motor, and the clutch driving means for driving the clutch mechanism is driven from outside of the stator housing, the number of parts is curtailed, and generation of imbalance in dewatering is suppressed. If water overflows from the outer tank due to some cause, water is prevented from entering inside of the drive motor, and if the clutch lever area is touched by hand by mistake, fingers are not caught into the drive motor, so that the safety is enhanced.